Spring clip safety IV catheter

ABSTRACT

A safety IV catheter includes a unitary, resilient needle guard received in a catheter hub. The needle guard includes a proximal arm or wall that includes an opening through which a needle passes for axial movement. When the needle is retracted from the catheter, it releases the force that had previously prevented movement of the needle guard within the catheter hub. This in turn causes the needle guard to snap into a position in which it is clamped onto the needle shaft and in which its distal wall blocks access to the needle tip. In this condition, the spring needle guard and needle can be removed from the catheter hub. A slot or crimp may be formed in the needle shaft that engages with the needle guard after the protected needle and needle guard are removed from the catheter hub, thereby to prevent removal of the protected needle from the needle guard.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of Ser. No. 10/734,931, filed Dec. 12, 2003 nowU.S. Pat. No. 8,211,070, which is a continuation-in-part of pendingapplication Ser. No. 10/445,166, filed May 23, 2003, now U.S. Pat. No.7,264,613, which is a continuation of application Ser. No. 09/638,641,filed Aug. 14, 2000, now U.S. Pat. No. 6,616,630, which is acontinuation-in-part of application Ser. No. 09/183,697, filed Oct. 30,1998, now U.S. Pat. No. 6,287,278, which is a continuation-in-part ofapplication Ser. No. 09/097,170, filed Jun. 12, 1998, now U.S. Pat. No.6,117,108, which is a continuation-in-part of application Ser. No.08/915,148, filed Aug. 20, 1997, now abandoned, the contents of each ofwhich are expressly incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to intravenous (IV) catheters, and, inparticular, to a safety IV catheter in which the needle tip isautomatically covered after needle withdrawal to prevent the healthcareworker from making accidental contact with the needle tip.

BACKGROUND OF THE INVENTION

IV catheters are primarily used to administer fluids, sometimescontaining medications, directly into a patient's vascular system. Thecatheter is inserted into a patient's vein by a healthcare worker byusing a handheld placement device that includes a sharp tip needle. Theneedle is positioned in the interior hollow portion of the catheter withits tip extended slightly beyond the edge of the catheter. The end ofthe apparatus opposite the needle tip is made up of the needle connectedto a needle hub which is capable of being held by the healthcare workerduring the insertion procedure.

The insertion procedure contains four basic steps: (1) the healthcareworker inserts the needle and catheter together into the patient's vein;(2) after insertion into the vein with the needle point, the catheter isforwarded into the vein of the patient by the healthcare worker pushingthe catheter with his or her finger; (3) the healthcare worker withdrawsthe needle by grasping the hub end (opposite the point end) while at thesame time applying pressure to the patient's skin at the insertion sitewith his or her free hand; and (4) the healthcare worker then tapes thenow inserted catheter to the patient's skin and connects the exposed endof the catheter (the catheter hub) to the source of the fluid to beadministered into the patient's vein.

The problem is that, immediately after the withdrawal of the needle fromthe patient's vein, the healthcare worker, who is at this time involvedin at least two urgent procedures, must place the exposed needle tip ata nearby location and address the tasks required to accomplish theneedle withdrawal. It is at this juncture that the exposed needle tipcreates a danger of an accidental needle stick occurring, which, underthe circumstances, leaves the healthcare worker vulnerable to thetransmission of various dangerous blood-borne pathogens, including AIDSand hepatitis.

This danger to the healthcare worker from accidental needle sticks hascaused an impetus for the development of a safer IV catheter in whichthe occurrence of such accidental needle sticks is prevented. Safetycatheters that have been developed to achieve this result are disclosed,for example, in Lemieux Reissue Pat. No. Re. 34,416, Crawford U.S. Pat.No. 5,558,651, McLees U.S. Pat. No. 5,135,504, Gaba U.S. Pat. No.5,697,907, and Dombrowski U.S. Pat. No. 4,978,344, Kulli U.S. Pat. No.4,929,241 and Chamuel U.S. Pat. No. 5,053,107 disclose a protectiveneedle guard for use with a hypodermic needle.

The prior art safety catheters all exhibit one or more drawbacks thathave thus far limited their usefulness and full acceptance by healthcareworkers. For example, in the safety catheter disclosed in the Lemieuxpatent, the force required to engage the needle slot within the guardflange is relatively great and would interfere with the removal of theneedle. Reducing this force to a more acceptable level would create thepossibility of the needle guard remaining in the catheter hub after theneedle is removed from the catheter. As a result, the safety catheterdisclosed in the Lemieux patent would not consistently function in areliable manner.

Similarly, the user of the safety catheter disclosed in the Dombrowskipatent would have to exert a considerable force to remove the protectivecap from the catheter hub when the cap engages a needle. The safetycatheter disclosed in the Dombrowski patent would also be relativelyexpensive to fabricate because of its inclusion of a flexible flange anda tether.

The McLees protective device requires an irksome extra pulling action ortug on the needle guard through a retention ring to remove the protectedneedle from the catheter hub. The McLees device also requires theassembly of two separate components and is thus relatively costly tomanufacture. In addition, the needle in the McLees device includes alarger diameter portion near and at the needle tip. This feature of theMcLees device would require that the remainder of the needle be of alesser diameter which would have the adverse effect of slowing the bloodflashback through the needle.

SUMMARY OF THE INVENTION

It is accordingly an object of the present invention to provide a safetyIV catheter which reliably and automatically prevents accidental,inadvertent contact with the needle tip after use.

It is a further object of the invention to provide a safety catheterwhich provides reliable protection to the healthcare practitioneragainst needle sticks without requiring any change in the manner of useof the safety catheter by the practitioner.

It is another object of the present invention to provide a safety IVcatheter of the type described which is relatively simple andinexpensive to manufacture.

It is yet a further object of the present invention to provide a safetycatheter of the type described in which removal of the needle from theneedle guard after use is prevented.

To these ends, the safety IV catheter of the invention includes aresilient spring clip needle guard that includes a distal or front endand a proximal or rear wall. The spring clip is inserted into thecatheter hub and is urged by the needle shaft into contact with theinner walls of the catheter hub so that the needle guard is reliablyretained therein. When the needle is withdrawn from the catheter, theforce it had previously exerted on the needle guard is released, causingthe needle guard to pivot within the catheter hub until it clamps ontothe needle shaft. At this time, the distal end wall of the needle guardblocks the distal pointed end tip of the needle. In addition, the springclip and protected needle onto which it is clamped can be readily andsafely removed from the catheter hub. The needle may be provided with aslot or, alternatively, may be provided with a segment of increasedwidth, such as a crimp, which cooperates with the needle guard toprevent the inadvertent removal of the needle from the needle guardafter their removal from the catheter hub.

In another embodiment, an IV catheter apparatus is provided whichcomprises a tubular catheter having a proximal end and a distal end anda needle having a needle shaft and a tip, where the needle is receivedwithin the tubular catheter when in a ready position. A catheter hub isattached to the proximal end of the catheter, where the catheter hub hasa hollow interior and an inner wall. The needle is movable between theready position, in which the tip is outside of the catheter hub, and aretracted position, in which the tip is within the interior of thecatheter hub. A unitary needle guard is positioned in the interior ofthe catheter hub and includes a resilient portion engaged by the needleshaft when the needle is in its ready position. A section of theresilient portion of the needle guard is urged by the needle shaft intocontact with an interior wall of the catheter hub when the needle is inits ready position. An inwardly extending annular protrusion is formedon the interior wall of the catheter hub for engaging a segment of theneedle guard for retaining the needle guard in the catheter hub duringthe movement of the needle between its ready position and its retractedposition. The needle guard includes a distal wall extending from theresilient portion and spaced from the needle tip when the needle is inits ready position and movable within the interior of the catheter hubto a blocking position distal of the needle tip when the needle is inits retracted position in which the needle shaft no longer exerts aforce on the resilient portion of the needle guard, such that contactbetween the segment of the needle guard and the catheter hub isreleased.

In another embodiment of the spring clip safety catheter of theinvention, a retaining groove or bump is formed in the inner wall of thecatheter hub, which, in the ready position, engages a lower arm of thespring clip to aid in the retention of the spring clip in the catheterhub.

In yet a further embodiment of the spring clip safety catheter of theinvention, a slot is formed in the needle. After the spring clip haspivoted to its retracted position and the needle is clamped by thespring clip, further movement of the needle in the proximal directionwill cause the rear or proximal arm of the spring clip to seat in theslot, thereby to more securely clamp the needle shaft to the springclip.

In a further embodiment of the spring clip catheter guard of theinvention, a tether is connected to the needle hub and the spring clipguard to prevent the spring clip guard from being pulled off theprotected needle without requiring an excessive clamping forcetherebetween.

In yet a further embodiment of the invention, the spring clip needleguard is in the form of resilient intersecting arms, each terminating ata distal guard wall. When the needle is in the ready position, it passesthrough the guard and urges the resilient arms away from each other andagainst the inner wall of the catheter hub. When the needle is retractedpast the guard walls, the resilient arms spring to the safety positionin which both of the guard walls are positioned distally from the needletip, thereby to form a barrier that prevents inadvertent contact withthe needle tip.

To the accomplishment of the above, and to such further objects as mayhereinabove appear, the present invention relates to a safety IVcatheter as described with respect to presently preferred embodiments inthe following specification, as considered with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are semi-schematic views in partial cross-section of asafety IV catheter in accordance with a first embodiment of theinvention in the ready and retracted positions, respectively;

FIGS. 1C and 1D are semi-schematic views similar to FIGS. 1A and 1B of apossible variation to the embodiment illustrated therein;

FIGS. 2A and 2B are semi-schematic views in partial cross-section of asafety IV catheter in accordance with a second embodiment of theinvention in the ready and retracted positions, respectively;

FIGS. 3A and 3B are semi-schematic views in partial cross-section of asafety IV catheter in accordance with a third embodiment of theinvention in the ready and retracted positions, respectively;

FIGS. 4A and 4B are semi-schematic views in partial cross-section of asafety IV catheter in accordance with a fourth embodiment of theinvention in the ready and retracted positions, respectively;

FIGS. 5A and 5B are semi-schematic views in partial cross-section of asafety IV catheter in accordance with a fifth embodiment of theinvention in the ready and retracted positions, respectively;

FIGS. 6A and 6B are semi-schematic views in partial cross-section of asafety IV catheter in accordance with a sixth embodiment of theinvention in the ready and retracted positions, respectively;

FIGS. 7A, 7B and 7C are views in partial cross-section of a safety IVcatheter in accordance with a further embodiment of the invention in theready, engaged and retracted or protected positions, respectively;

FIGS. 7D and 7E are semi-schematic views similar to FIGS. 7A and & b ofa possible variation to the embodiment of the invention illustratedtherein;

FIG. 8 is a semi-schematic perspective of the spring clip needle guardused in the embodiment of FIG. 7;

FIG. 9 is a semi-schematic cross-section of the spring clip needle guardof FIG. 8;

FIGS. 10A and 10B are semi-schematic views in partial cross-section of asafety IV catheter in accordance with still a further embodiment of theinvention shown in the ready and protected positions, respectively;

FIGS. 11A and 11B are semi-schematic perspectives of the needle guardclip of the embodiment of FIG. 10;

FIG. 12 is a semi-schematic perspective view of a safety IV catheter inaccordance with another embodiment of the invention;

FIGS. 13A and 13B are semi-schematic cross-sectional views of theembodiment of the invention of FIG. 12 in the ready and protectedpositions, respectively;

FIG. 14 is a semi-schematic view in partial cross-section of a safety IVcatheter in accordance with still a further embodiment of the invention,wherein an inwardly extending annular protrusion is provided toreleasably retain the needle guard within the catheter hub;

FIG. 15 is a semi-schematic cross-sectional view taken along line 15 ofFIG. 14, showing a continuous generally annular protrusion;

FIG. 16 is a semi-schematic cross-sectional view similar to that of FIG.15, showing a generally annular protrusion having a small discontinuityformed therein;

FIG. 17 is a semi-schematic cross-sectional view similar to that of FIG.15, showing a two-part annular protrusion;

FIG. 18 is a semi-schematic side view of the needle of FIG. 14;

FIG. 19 is a semi-schematic side view of the needle of FIG. 18 rotated90 E about its longitudinal axis;

FIG. 20 is a semi-schematic perspective view of a tool used forassembling one configuration of the present invention;

FIG. 21 is a semi-schematic end view of alternative configuration of thepresent invention showing the needle guard oriented so as to facilitateinsertion within the catheter hub;

FIG. 22 is a semi-schematic end view of the alternative configuration ofFIG. 21, showing the needle guard after it has been rotated so as toremain within the catheter hub until the needle is moved to theprotected position thereof; and

FIG. 23 is a semi-schematic perspective view of an alternative needleguard comprising side flaps and extending arm sections.

DETAILED DESCRIPTION OF THE INVENTION

The safety IV catheter of the invention, generally designated 10 in theembodiment illustrated in FIGS. 1A and 1B, includes a needle hub 12 thatincludes an axial opening 14 which securely receives the proximal end ofa needle 16 having a sharpened tip 18. The needle hub 12, as isconventional, is hollow and includes a flash chamber 22. As is alsoconventional, the needle 16 is received within a hollow tubular catheter24, the proximal end of which is concentrically affixed within thedistal end of a catheter hub 26 having a distal section 28 and acontiguous, larger diameter proximal section 30.

The catheter hub 26 terminates at its proximal end in a Luer fitting 32adapted to receive a tubing set which, in a known manner, administersintravenous fluid into the patient. The catheter 24 is secured within anaxial passageway 34 in the distal hub section 28 by means of a sleeve 20received within the passageway 34, which engages the proximal end of thecatheter. Passageway 34 communicates at its proximal end with a flashchamber 36 formed in the hub section 30.

In the ready position of the catheter, shown in FIG. 1A, the distal endof the needle hub 12 is snugly received in the proximal end of theinterior of the chamber 36 such that the needle 16 extends through thechamber 36, the passageway 34, and distally beyond the catheter hub 26and catheter 24, so that its tip extends beyond the tapered distal endof the catheter.

In use, the distal tip of the needle and the catheter are inserted intoa patient's vein. Thereafter, the healthcare practitioner manuallyplaces the catheter further into the vein and then withdraws the needleby grasping and moving by hand the proximal end of the needle hub 12.The Luer of the catheter hub 26 is then fitted with a source of thefluid that is to be administered into the patient's vein.

In accordance with the present invention, as the needle 16 is beingwithdrawn from the patient, a protective needle guard 40 located withinthe hub chamber 36 automatically snaps into a retracted position inwhich it blocks access to the distal needle tip and prevents furtherdistal movement of the needle tip, thereby to prevent accidental contactby the healthcare practitioner with the needle tip.

As shown in FIGS. 1A and 1B, the needle guard 40 is in the form of aunitary spring clip that is preferably made of a resilient metal such asstainless steel. The spring clip includes a distal arm 42 terminating atits upper end in a curved lip 44 and at its lower end in a pointed end46 which, in the embodiment of FIG. 1, is received within a matinggroove 48 formed in the lower interior wall of the catheter hub section30.

The spring clip needle guard 40 further includes a transverse segment 50that extends upward and proximally from the lower pointed end 46 andterminates at a U-shaped upper end 52. In the ready position of thespring clip shown in FIG. 1A, the upper end 52 abuts against the upperinterior wall of the catheter hub section 30. The spring clip guard 40further includes a vertical arm 54 that extends downward from theU-shaped upper end 52 and terminates above the lower wall of thecatheter hub section 30. The transverse segment 50 and proximal verticalarm 54, respectively, include axially aligned openings 56, 58 throughwhich the shaft of the needle 16 is free to pass and axially move. Thediameter of the opening 58 is slightly greater than that of the needleshaft, whereas the diameter of the opening 56 is greater than that ofthe opening 58.

In the ready position of the catheter prior to needle withdrawal, theshaft of the needle 16 engages the curved lip 44 of the spring clipneedle guard 40, thereby to exert an essentially downward force on theresilient spring clip. That force causes the lower end 46 of the springclip to seat securely in the groove 48 at point A. That contact, inaddition to the abutment of the upper end 52 of the spring clip with theupper interior wall at the catheter hub at point B, securely maintainsthe spring clip needle guard 40 in the ready position within thecatheter hub.

As the needle 16 is retracted to the left, as viewed in FIG. 1A, to itsfully retracted position, shown in FIG. 1B, after catheter insertioninto the patient's vein, the distal tip of the needle moves proximallypast the curved lip 44 of the spring clip needle guard 40 at point C, atwhich time the downward force previously exerted by the needle shaft onthe spring clip is released.

As a result of the needle 16 moving proximally past point C, theretention force on the spring clip needle guard 40 in the catheter hubis released, causing the spring clip needle guard 40 to pivot or snap ina clockwise direction to the retracted position shown in FIG. 1B. Astherein shown, distal arm 42 of the needle guard 40 blocks the distalpath of the needle 16. Simultaneously with the blocking and releasingactions, the spring clip guard 40 becomes securely clamped onto theneedle shaft at points D and E, thereby to securely lock the needleguard 40 onto the needle shaft. At this time, the needle 16 and needleguard 40 can be removed together from the catheter hub 26, and the tipof the needle cannot be pushed past the needle guard because it isblocked by the distal arm 42 and lip 44 of the needle guard.

If desired, a slot 60 may be formed in the needle shaft slightlyproximal to the needle tip. When the needle and the needle guard are intheir retracted and clamped positions (FIG. 1B), slot 60 is positionedslightly distal to the clamping point E of the transverse segment of theneedle guard 40 such that if a subsequent attempt is made to move theneedle further in a rearward or proximal direction, the transversesegment 50 at point E will seat into slot 60, thereby to provide anadditional force to retain the needle guard 40 on the needle 16 in theprotected position in which access to the needle tip is prevented.

The safety IV catheter illustrated in FIGS. 1C and 1D is the same asthat illustrated in FIGS. 1A and 1B, except that the slot 60 in theneedle shaft in the latter is replaced in the former by a crimp 61 whosewidth is greater than that of the opening 58 in the vertical arm 54. Ifan attempt is made to move the protected needle illustrated in FIG. 1Cin the rearward or proximal direction, the crimp 61 will engage the wall54 and will thus not be able to pass through the opening 58, so as toprevent further proximal movement of the needle and removal of theneedle from the needle guard, as defined.

The embodiment of the invention illustrated in FIG. 2 is similar to thatof FIG. 1 except that, instead of the groove formed in the lower wall ofthe catheter hub that engages the lower end of the spring clip, aretaining bump 62 is formed in that wall against which the lower end 46of the needle guard 42 seats when the needle guard 40 is in the readyposition, as shown in FIG. 2A.

The embodiment of the invention illustrated in FIGS. 3A and 3B isessentially the same as that of FIG. 2 with the addition of a tether 64secured at one end to the needle hub 12 and at its other end to theproximal arm 54 of the spring clip needle guard 40. As shown in FIG. 3B,the tether 64 is extended to its full length when the needle hub isretracted to achieve needle removal, so as to more securely retain theneedle hub 12 and the spring clip needle guard 40 when the latter isclamped onto the needle when in the retracted position in which, asdescribed above, the distal arm 42 of the spring clip prevents access tothe needle tip, and the needle guard 40 and needle are released from thecatheter hub.

FIGS. 4A and 4B illustrate a spring clip needle guard embodying theprinciples of the invention in an alternative configuration. As thereinshown, the spring clip needle guard 40 a includes a distal arm 65terminating at its upper end in a curved lip 66 and at its lower end ina U-shaped portion 67 which, in the ready position illustrated in FIG.4A, contacts a bump 68 formed in the lower inner wall of the catheterhub.

A transverse segment 69 having a central opening 70 extends proximallyand upwardly and terminates at an upper U-shaped portion 72. A proximalend wall 74 having an opening 76 depends vertically from portion 72 andthen extends distally in a horizontal lower segment 78 which has anopening 80 through which the lower halves of the distal arm 65 and thetransverse segment 69 extend in the ready position of the needle guard.Segment 78, at its distal end, extends upwardly at a front wall 82 whichhas a central opening 84 axially aligned with openings 70, 76. At itsupper end, the distal front wall 82 extends in the proximal direction inan upper segment 86 which, as shown in FIG. 4A, contacts the upper innerwall of the catheter hub along substantially its entire length.

As shown in FIG. 4A, when the catheter is in the ready position, theneedle shaft passes through openings 70, 76 and 84 and rests on thecurved lip 66, urging the arm 65 against the bump 68 in the lower wallof the catheter hub. That engagement, along with the resilientengagement of the upper segment 86 with the upper interior wall of thecatheter hub, retains the spring clip 40 a in its ready position withinthe catheter hub.

When the needle hub and needle are retracted to the right, as viewed inFIG. 4A, by a sufficient amount, the needle tip passes below the lip 66and then releases its downward force on the arm 65. As described abovewith reference to the first-described embodiment, this release ofengagement of the needle shaft and the spring clip arm 65 causes the arm65 to snap upwards to the retracted position illustrated in FIG. 4B, inwhich the arm 65 and the lip 66 extend over the needle tip and therebyprevent accidental contact with the needle tip as desired. In thiscondition, the needle guard is clamped onto the needle shaft inessentially the same manner described above with respect to thefirst-described embodiment, and the needle and needle guard clampedthereto can be readily removed from the catheter hub, also as describedabove and as shown in FIG. 4B.

The embodiment of the needle guard illustrated in FIGS. 5A and 5B isessentially the same as that shown in FIGS. 4A and 4B, with the additionof a slot 90 near the distal tip end of the needle. When the needle andneedle guard are in their retracted and clamped position (FIG. 5B), theslot 90 is positioned slightly distal to the clamping point of thetransverse segment 69 such that if a subsequent attempt is made to movethe needle further in a rearward or proximal direction, the transversesegment 69 will seat into the slot 90, thereby to provide an additionalforce to retain the needle guard in the needle in the protected positionin which access to the needle tip is prevented.

The embodiment of the invention illustrated in FIGS. 6A and 6B is thesame as that illustrated in FIGS. 4A and 4B, except for the inclusion ofa tether 92 secured at one end to the needle hub and at its other end tothe proximal wall of the spring clip needle guard. As shown in FIG. 6A,in the ready position, the tether is wound around the distal end of theneedle hub. As shown in FIG. 6B, when the needle and needle guard are intheir retracted position, the tether is extended to its full length andaids in the retention of the needle guard to the needle hub. If desired,the embodiment of the invention embodiment illustrated in FIGS. 6A and6B could also include a needle slot as in the embodiment of theinvention illustrated in FIGS. 5A and 5B.

The embodiment of FIGS. 7A-7C differs from the previously describedembodiments primarily with regard to the construction and operation ofthe spring clip needle guard 96. As shown in FIGS. 8 and 9, the springclip 96 includes a central transverse section 98 which includes acentral slot 100. A sloping section 102 extends from section 98 in theproximal direction and terminates at a curved end 104 from which aproximal vertical arm 106 extends. The arm 106 terminates at its lowerend in a U-shaped section 108. The distal end of the transverse section98 terminates in a curved section 110 from which a vertical proximal arm112 extends. The distal arm 112 terminates at its upper end in a curvedarm 114.

A cutout portion in section 98 defines a flexible flap 116 whichterminates at its distal free end in a downwardly sloping locking tab18. As in the prior embodiments, the proximal arm 106 includes anopening 58.

As shown in FIG. 7A, the spring clip needle guard 96, when in the readyposition illustrated therein, is inserted within the catheter hub 26 soas to allow the needle 16 to pass through the opening 58 and slot 100.As in the previously described embodiments, the curved end 104 abutsagainst the inner upper wall of the catheter hub 26 at point B, and thecurved section 110 seats within the mating groove 48 at point A formedin the lower inner wall of the catheter hub. In addition, the lowercurved section 108 contacts at point F the lower inner wall of thecatheter hub 26 at a location proximal to point B.

In operation, the needle is initially withdrawn into the catheter hubuntil it reaches the tab engaged position illustrated in FIG. 7B inwhich, as therein shown, the locking tab 118 is received within theneedle groove or slot 60. At this point, the spring clip remains incontact with the inner wall of the catheter hub at points A, B and F,while the needle tip 18 engages the curved end 114, thereby to urgesection 110 into the groove 48 at point C. The relative position ofpoint F with respect to point B prevents the needle and clip from beingprematurely released from the catheter hub by preventing the distal endof the clip from tipping upwards and the proximal end from slippingdownward with the clip in the tab engaged position shown in FIG. 7B.

As the needle is withdrawn further away from the patient, as shown inFIG. 7C, the needle tip passes beyond the curved end 114, therebyreleasing the downward force that had been previously exerted on thecurved end 114 by the needle.

This sudden release of the downward force on the spring clip end causesthe distal end of the spring clip 96 to pivot upward so that the distalend 112 of the spring clip 96 moves rapidly to a position in which itprevents or blocks the motion of the needle in the distal direction. Thespring clip 96 is retained on the needle 16 and will be removed from thecatheter hub 26 when the needle is completely removed. Movement of thespring clip 96 from its protecting or retracted position shown in FIG.7C is further prevented by the insertion of the locking tab 118 into theneedle groove 60, which prevents the spring clip from rotating aroundthe periphery of the needle. This, in turn, secures the spring clip onthe needle, even if the clip were subjected to a twisting and pullingforce.

The safety IV catheter illustrated in FIGS. 7D and 7E is the same s thatillustrated in FIGS. 7A and 7B, except that the slot 60 in the needleshaft in the latter is replaced in the former by a crimp 61 whose widthis greater than that of the opening 58 in the vertical arm 54. If anattempt is made to move the protected needle illustrated in FIG. 7D inthe rearward or proximal direction, the crimp 61 will engage the wall 54and will not be able to pass through the opening 58, so as to preventany further proximal movement of the needle and removal of the needlefrom the needle, as desired.

The embodiment of the spring clip needle guard 120 disclosed in FIGS.10A, 10B, and 11 comprises first and second arms 122 and 124,respectively, joined at their proximal ends in a hinged arrangement at125 to the ends of a rear wall 126. The distal ends of the arms 122, 124each include a curved protrusion 128 extending to a distal end wall 130,which, in turn, terminates in a lip 132. As seen best in FIG. 11, therear wall 126 includes a central opening 134, and the arms 122 and 124each include a narrow portion 142 that extends between a distal wideportion 140 and a proximal wide portion 144. A lateral clamping edge 146is defined at the distal wide portion 144.

As shown in FIG. 10A, when the needle guard 120 is in its readyposition, the curved protrusions 128 in each of the arms 122, 124 arereceived in an annular groove or ring 136 formed in the inner wall ofthe catheter hub 26 which, as in the prior embodiments, is removably fitinto the distal end of a needle hub 12. Also as in the prior embodiment,a needle 16 having a sharpened tip 18 at its distal end is receivedwithin a tubular catheter 24 which is secured t the distal end of thecatheter hub 26. The proximal end of the needle 16 passes through theopening 134 in the rear wall 126. The needle 16 includes an crimp 138which is sufficiently small to allow the needle 16 to move axially alongthe catheter 24 but is greater in width than the opening 134 for reasonsto be described below.

In the ready position illustrated in FIG. 10A, the needle shaft passesthrough the needle guard and applies an outward radial force on theresilient arms 122, 124 by means of its engagement with the lips 132, soas to urge the curved protrusions 128 of each of the arms into theannular groove 136, so as to retain the needle guard 120 in a fixedposition within the inner wall of the catheter hub 26. The shaft of aneedle 16 that passes through the needle guard 120 frictionally engagesthe inner edges of the narrow portion 142 of arms 122, 124 so as tofurther retain the needle in its ready position.

When the needle is retracted axially to the right, as viewed in FIG.10A, within the catheter hub and moves past the end lip 132 of theneedle guard, the radial force previously exerted on the arms 122, 124of the needle guard 120 is suddenly released. This causes the distal endwalls 130 of the needle guard to be released from their seat in theannular groove 136 and to pivot inward into the catheter hub until, asseen in FIG. 10B, the end walls 130 overlap one another at a locationdistally in front of the needle tip, thereby to form a barrier thatprevents inadvertent contact with, and distal movement of, the needletip. At the same time, the clamping edges 146 of the needle guard areurged against the needle tip to restrict further axial movement of theneedle.

As also shown in FIG. 10B, the needle guard 120 and the needle clampedto the needle guard after needle retraction can be removed from thecatheter hub as a unitary assembly and safely discarded. If an attemptis made, intentionally or inadvertently, to pull the needle further tothe right, as shown in FIG. 10B, out of the needle guard, the crimp 138on the needle shaft will come into contact with the end wall 126, and,since its width is greater than that of the opening 134, the end wall126 will at this point prevent any further axial movement of the needleout of the needle guard.

This spring clip guard of the invention, in the embodiment illustratedin FIGS. 12, 13A and 13B, includes a transverse arm 150 terminating atits distal end at a distal end wall 152, which includes at its upper enda curved lip 154 and at its lower end a curved end 156. An elongatedrectangular opening or slot 158 is provided in the transverse arm 150.The proximal ends of the transfer arm 150 and the opening 158 terminateat an extension 160 extending upwardly at an angle from the arm 150 andhaving a finger or flap 162 that extends toward the opening 158.

The proximal end of the extension 160 terminates t a curved end 166 fromwhich a proximal end wall 168 extends downwardly. The wall 168, whichincludes an opening 170, terminates at its lower end at a curved section172 from which extends an upwardly sloping arm 174 that terminates at aclamping edge 176. As can be seen in FIGS. 13A and 13B, a 360 E circulargroove 178 is formed about the circumferential wall of the needle 16slightly inwardly from the tip 18 of the needle.

In the ready position of the spring clip guard of FIG. 12, asillustrated in FIG. 13A, the shaft of the needle passes through thealigned opening 170 in the rear wall 168 and the opening 158 in thetransverse arm 150 and extends distally beyond the catheter hub. As inthe prior embodiments described hereinabove, the needle shaft in thisposition exerts a downward radial force on the arm 150 by means of itsengagement with the curved lip 154. This downward force urges the curvedend 156 of the spring clip to seat firmly within a groove 164 formed inthe inner wall of the catheter hub at point A.

At the same time, the upper curved end 166 of the end wall 168 engagesthe inner wall of the catheter hub at point B, and the lower curved end172 of the wall 168 engages the inner wall of the catheter hub at pointF. Further engagement between the needle shaft and the spring clip isprovided by the contact of the finger 162 with the upper end of theneedle shaft at point E and between the clamping edge 176 and the lowersurface of the needle shaft at point G. In this manner, the needle issecurely but movably retained within the catheter hub in its readyposition.

When the needle is retracted axially to the right, as viewed in FIGS.13A and 13B, it eventually moves past its engagement with the lip 154,thereby to suddenly release the radial force it had previously exertedon the arm 150 of the needle guard. This release of engagement betweenthe needle shaft and the lip 154 allows the distal curved end 156 of thedistal end wall 152 of the spring clip to be released from its seat inthe annular groove 164 so that the aim 150 and the end wall 152 pivotquickly into the interior of the catheter hub, as seen in FIG. 13B, to aposition at which the wall 152 forms a barrier to the needle tip. Thispositioning of the wall 15 prevents inadvertent contact with the needletip. The engagement of the finger 162 and the clamping edge 176 to theopposing sides of the needle prevents further axial movement of theneedle in either direction.

If an attempt is thereafter made to pull the needle axially further tothe right, as viewed in FIG. 13B, the finger 162 will enter the circulargroove 178 formed in the needle surface, thereby to prevent furtheraxial movement of the needle in the proximal direction out of the needleguard.

As shown in FIG. 14, yet a further embodiment of the present inventionis generally similar to the embodiment shown in FIG. 10A, with thenotable exception that the annular groove or ring 136 of the embodimentshown in FIG. 10A has been replaced with an inwardly extending annularprotrusion 136 a which serves an analogous function with respect to theannular groove or ring 136. Preferably, the annular protrusion 136 aextends completely around the interior of the catheter hub 26 in agenerally continuous ring-like fashion.

The annular protrusion 136 a removably retains the needle guard 120within the catheter hub 26 as the needle 16 is withdrawn from thecatheter hub 26, until the arms 122, 124 of the needle guard 120 moveinwardly as the tip 18 of the needle 16 moves past the end lips 132 ofthe needle guard 120, as discussed in detail above.

Although the annular protrusion 136 a is shown in FIG. 14 as having agenerally semi-circular cross-section, those skilled in the art willappreciate that various other cross-sectional configurations of theannular protrusion 136 a are likewise suitable. For example, the annularprotrusion 136 a may alternatively have a generally triangular, square,rectangular, or any other desired cross-sectional configuration.

The annular protrusion 136 a is preferably formed integrally withrespect to the catheter hub 26, such as being injection molded as aportion thereof Alternatively, the annular protrusion 136 a may beformed separately from the catheter hub 26 and attached to the catheterhub 26 via adhesive bonding, ultrasonic welding or any other desiredmethod.

Moreover, it will be appreciated that the annular protrusion 136 a mayhave any desired configuration which releasably retains the needle guard120 within the catheter hub 26 until the tip 18 of the needle 16 hasbeen withdrawn past the lips 132 of the needle guard 120.

As shown in FIGS. 14 and 15, when the needle guard 120 is in its readyposition, the curved protrusions 128 in each of the arms 122, 124 arepositioned near, e.g., in abutting contact with, the annular protrusion136 a formed on the inner wall of the catheter hub 26 which, as in theprior embodiments, is removably fit onto the distal end of a needle hub12. Also, as in the prior embodiment, a needle 16 having a sharpened tip18 at its distal end is received within a tubular catheter 24 which issecured to the distal end of the catheter hub 26. The proximal end ofthe needle 16 passes through the opening 134 in the rear wall 126 of theneedle guard 120. The needle 16 includes an crimp 138 which issufficiently small to allow the needle 16 to move axially along thecatheter 24 but which is greater in width than the opening 134 forreasons to be described below.

In the ready position illustrated in FIGS. 14 and 15, the needle shaftpasses through the needle guard 120 and applies an outward radial forceon the resilient arms 122, 124 by means of its engagement with the lips132, so as to urge the curved protrusions 128 of each of the armsagainst the inner wall of the catheter hub 26, so as to retain theneedle guard 120 in a fixed position within the catheter hub 26. As wasthe case with the embodiment described with respect to FIGS. 10A and10B, the shaft of a needle 16 that passes through the needle guard 120and optionally frictionally engages the inner edges of the narrowportion 142 (shown in FIG. 11) of arms 122, 124 so as to further retainthe needle in its ready position.

When the needle is retracted axially to the right, as viewed in FIG. 14,and moves past the end lips 132 of the needle guard 120, the radialforce previously exerted on the needle guard arms 122, 124 is suddenlyreleased. The annular protrusion 136 a prohibits movement of the needleguard 120 to the right as the needle 16 moves to the right, until thetip 18 past the end lips 132 of the needle guard 120. Movement of thetip 18 past the end lips 132 allows the resilient arms 122, 124 andtheir protrusions 128 therein to move inwardly a sufficient distance tocease abutting the annular protrusion 136 a. As was the case with theembodiment described with regard to FIGS. 10A and 10B, the distal endwalls pivot inward into the catheter hub until the end walls overlap oneanother at a location distally in front of the needle tip, thereby toform a barrier that prevents inadvertent contact with, and distalmovement of, the sharpened needle tip 18. At the same time, the clampingedges 146 of the needle guard (as described with respect to FIG. 11) areoptionally urged against the needle 16 to restrict further axialmovement of the needle, in relation to the needle guard 120.

As again shown in FIG. 10B (which shows the needle 16 and the needleguard 120 removed from the catheter hub 26 and is thus applicable toboth the embodiment of FIG. 10A and the embodiment of FIG. 14), theneedle guard 120 is fixedly attached to the needle 16 after needleretraction, such that the needle guard and the needle can be removedfrom the catheter hub as a unitary assembly and safely discarded. If anattempt is made, either intentionally or inadvertently, to pull theneedle further to the right (as viewed in FIG. 10B) out of the needleguard, the crimp 138 on the needle shaft will come into contact with theend wall 126, and, since the crimp width is greater than the diameter ofthe opening 134, the end wall 126 will, at this point, prevent anyfurther axial movement of the needle out of the needle guard.

As shown in FIG. 16, the inwardly extending, generally annularprotrusion 136 b may alternatively be formed to have a generallyC-shaped configuration. Optionally, the C-shaped protrusion 136 b may bedefined by a metal snap ring which is partially disposed within agroove, such as groove 136 of FIG. 10 a. Thus, the inwardly extending,generally annular protrusion 136 b may be formed by sliding a metal snapring into the catheter hub 26 until the metal snap ring snaps into agroove formed within the catheter hub 26.

As shown in FIG. 17, as a further alternative the inwardly extending,generally annular protrusion 136 c may be defined so as to have twogenerally semi-circular segments or portions. Indeed, those skilled inthe art will appreciate that various different configurations of theinwardly extending, generally annular protrusion are likewise suitable.

Thus, the inwardly extending, generally annular protrusion may have anydesired configuration. It is preferred that the inwardly extending,generally annular protrusion not have any gap(s) 137 (as shown in FIGS.16 and 17) which have a width greater than the width of the distal endwalls 130 of the needle guard 120. Sizing the gaps 137 so as to besmaller than the width of the end walls tends to prevent the needleguard 120 from passing through such gaps 137 and thereby undesirablyallowing the needle guard 120 to slip out of the needle hub 26 withoutproperly protecting the tip 18 of the needle 16. Thus, according to thepresent invention, any desired number of separate sections may beutilized to define the inwardly extending, generally annular protrusion,as long as the needle guard 120 is effectively held in place thereby asthe needle 14 is withdrawn from the catheter 24.

As shown in FIGS. 18 and 19, the crimp 138 formed in the needle 16preferably defines a pair of generally opposed, outwardly extendingbulges 138 a in the needle and also defines a pair of generally opposed,inwardly extending depressions 138 b, which are disposed generallyorthogonally with respect to the bulges 138 a. The bulges 138 a define acrimp 138 having a width, dimension W, which is small enough tofacilitate movement of the needle 16 within the catheter 24, as shown inFIG. 14, and which is too large to pass through the central opening 134formed in the end wall 126 of the needle guard 120, as discussed above.

The crimp 138 may be formed by any contemporary crimping process, suchas those processes wherein two jaws of a vise or crimper come togetherso as to squeeze the needle 16 in a manner which forms the depressions138 b of FIG. 19, thereby consequently also forming the bulges 138 a.

The IV catheter shown in FIG. 14 is assembled by sliding the needleguard 120 over the sharpened tip 18 of the needle 16 before the crimp138 is formed in the needle 16. The needle 16 passes through the opening134 formed in the end wall 126 of the needle guard 120. The distal arms132 are opened and the needle 16 passes through them. Next, the crimp138 is formed in the needle 16, so that the needle guard 120 is capturedbetween the crimp 138 and the needle hub 12.

Next, the needle 16, having the needle guard 120 thereon, is slid intothe catheter hub 26 such that the sharpened tip 18 of the needle 16enters the catheter 24. The needle 16 is slid into the catheter 24 untilthe curved protrusions 128 of the needle guard 120 abut the annularprotrusion 136A.

Once the curved protrusions 128 abut the annular protrusion 136A, theneedle guard 120 ceases to move along with the needle 16. The needleguard 120 may cease to move along with the needle 16 before the curvedprotrusions 128 of the needle guard 120 abut the annular protrusion136A, since the inner surface of the catheter hub 26 tapers inwardly,such that the inside diameter thereof is reduced as the needle guard 120travels further into the catheter hub 26. Thus, the needle guard 120 maycease moving along with the needle 16 due to such narrowing of theinside of the needle guard 26, when the inside diameter of the catheterhub 26 becomes too small for the needle guard 120 to pass furthertherethrough.

Once the needle guard 120 has ceased to move along with the needle 16 asthe needle is inserted into the catheter 24, a tool is used to gentlyurge the needle guard 120 further into the catheter hub 26, until thecurved protrusions 128 of the needle guard 120 pass beyond the annularprotrusion 136A. Sufficient force must be applied to the needle guard120 via the tool so as to cause the curved protrusions of the needleguard 120 to flex toward one another such that they pass beyond theannular protrusion 136A.

After the curved protrusions 128 of the needle guard 120 have passedbeyond the annular protrusion 136A and have flexed back outwardly,generally so as to contact the inner wall of the catheter hub 26, thenthe needle guard 120 is in the ready position as shown in FIG. 14.

The tool used to urge the needle guard 120 past the annular protrusion136 within the catheter hub 26 may comprise any convenient structuresuitable for such use. For example, as shown in FIG. 20, a simple pin200 with a slot 202 running the length thereof (so as to receive theneedle 16 as the needle guard 120 is pushed) may suffice.

Thus, when the IV catheter of the present invention is assembled, thecurved protrusions 128 of the needle guard 120 positively engage theinwardly extending annular protrusion 136A such that the needle guard120 remains within the catheter hub 26 as the needle 16 is withdrawnfrom the catheter 24, until the sharpened tip 18 of the needle passesbetween the lips 132 of the needle guard 120 so as to disengage thecurved protrusions 128 with respect to the annular protrusion 136A toallow the needle guard 120 to move out of the catheter hub 26 along withthe needle 16.

An alternative method for assembling the spring clip safety I.V.catheter of the present invention may be utilized when the annularprotrusion is configured as a C-shaped protrusion or an open ring 136 b,as shown in FIG. 16 and is formed separately from the catheter hub 26.In this instance, the open ring 136 b can be placed upon the needleguard 120 (between the proximal and distal ends thereof) after theneedle 16 has been passed through the needle guard 120 and crimped.Then, both the needle guard 120 and the open ring 136 b may besimultaneously pushed into the catheter hub 26 utilizing the same tool.

This tool preferably has at least two fingers, one of which extendsalong each side of the needle guard 120, so as to push the open ring 136b further into the catheter hub 26 than the proximal end of the needleguard 120. In this manner, the needle guard 120 does not have to bepushed over the annular protrusion 136. Rather, the needle guard 120 andthe annular protrusion 136 b are assembled together, i.e., along withone another. The annular protrusion 136 b is thus assembled into thecatheter hub 26 so as to lock the needle guard 120 into position, wherethe needle guard 120 remains until the needle 16 is moved to theprotective position thereof, as discussed in detail above.

Referring now to FIGS. 21 and 22, yet a further alternative method forassembling the needle guard 120 a into the catheter hub 26 is shown.According to this alternative method, the annular protrusion 136 d isconfigured so as to have at least four openings 137 formed therein andis configured so that the needle guard 120 a may pass through theopenings 137 utilizing very little or no insertion force. After theneedle guard 120 a has been pushed into the catheter hub 26 past theannular protrusion 136 d, then the needle guard 120 a is rotated so asto position the four corners 250 thereof behind the annular protrusion136 d as shown in FIG. 22, which then functions so as to maintain theneedle guard 120 a with the catheter hub 26 until the needle 16 iswithdrawn and moved into the protective position thereof, as discussedin detail above.

It may be desirable to form the needle guard 120 a so as to provide agenerally square profile, as shown in FIGS. 21 and 22. However, as thoseskilled in the art will appreciate, various different generally square,rectangular or other profiles of the needle guard 120 a are likewisesuitable. It is merely necessary to locate the openings 137 formed inthe annular protrusion 136 d such that the needle guard 120 a is readilyreceived therebetween during the assemble process and is then held inplace thereby, after rotating the needle guard 120 a so as to place thecorners 250 thereof into abutting contact with the annular protrusion136 d.

Referring now to FIG. 23, a semi-schematic perspective view of analternative protector clip or spring clip needle guard 182 provided inaccordance with aspects of the present invention is shown. The protectorclip 182 is similar to the needle guards described above with a fewchanges and may be used with the needle assemblies described above. Inone exemplary embodiment, the first aim 184 and the second arm 186 eachincorporates an arm extension member 188 adjacent an edge 190 of therespective arms. Preferably, the arm extension members 188 of the twoarms project inwardly from a first arm surface 192 of the respectivearms 184, 186 in the direction of the needle, assuming that one passesthrough the central opening 134 of the rear wall 126. Alternatively, thearm extension members 188 may project outwardly from the second armsurface 194 away from the needle. Because the two arms 184, 188 crossone another, as shown, there may be sections of the arm extensionmembers 188 that project in the direction of the needle while otherportions project away from the needle.

In one exemplary embodiment, the arm extension members 188 comprise aflap or a wing stamped from a metal sheet, such as a stainless steelsheet, as part of forming the protective clip 182 and bent eitherinwardly towards the needle or outwardly away from the needle. The armextension members 188 have a length that can vary. In one exemplaryembodiment, the length of the arm extension members extend a substantiallength of the first and second arms 184, 186. More particularly, the armextension members extend from approximately just distal of the hingedsection 125 to approximately just distal of the proximal wide portion144. However, the length can also extend longer or short than asdescribed. For example, in one exemplary embodiment, the arm extensionmembers 188 can have a length approximately the length of the narrowportions 142 of the first arm 184 and the second arm 186. Although notrequired, the ends 196 of the arm extension members 188 may be taperedto eliminated sharp edges. In an alternative embodiment, the armextension members 188 may be eliminated entirely or formed on only oneof the first or the second arm.

In one exemplary embodiment, two side flaps 198 project inwardly in thedirection of the needle are formed on the finger or lip 132 of thesecond arm 186. Similar to the arm extension members 188, the side flaps198 are formed when forming or stamping a sheet of metal for theprotector clip 182 and bent inwardly in the direction of the needle. Theside flaps 198 each comprises a top section 200 and two sides 202, 204.Although the sides 204 furthest proximal of the distal wall terminateevenly with the edge 206 of the lip 132, the side flaps 198 may beshifted distally and the edges 204, 206 offset. The side flaps 198should be of sufficient size to delimit the needle from moving away oroutside the space defined by the two side flaps upon activation of theprotective clip 182 over the needle tip.

In an alternative embodiment, the finger or lip 132 of the first arm 184may incorporate the side flaps 198 instead of the finger or lip 132 ofthe second arm 186. Still alternatively, both fingers or lips 132 of thefirst arm 184 and the second arm 186 may incorporate side flaps for atotal of four side flaps.

It will thus be appreciated that the spring clip needle guard of theinvention as employed in an IV catheter provides automatic and reliableprotection of the needle tip upon needle retraction to preventaccidental contact with the needle tip by a healthcare practitioner Itwill also be appreciated that modifications may be made to theembodiments of the invention specifically described hereinabove withoutnecessarily departing from the spirit and scope of the invention.

1. An intravenous catheter assembly comprising: a catheter hub having anelongated tubular catheter extending therefrom, said catheter hubcomprising a proximal end, a distal end, and an interior cavity havingan internal surface; a needle hub having a needle received within saidtubular catheter when in a ready position; said needle having a proximalend, a sharpened distal end, a needle surface defining a needle shafthaving a nominal diameter, and a reduced diameter shaft section proximalof the sharpened distal end, which is smaller in diameter than thenominal diameter, said needle being movable between a ready position inwhich said sharpened distal end extends distally of the distal end ofsaid tubular catheter and a retracted position in which the sharpeneddistal end is within the interior cavity of the catheter hub; a needleguard for shielding the tip of the needle slidably mounted on saidneedle, said needle guard having a proximal end and a distal end;wherein said proximal end comprises a proximal wall comprising aproximally facing wall surface, a distally facing wall surface, and anopening having a fixed circumference having the needle passingtherethrough; wherein said proximal wall comprises a first edge and asecond edge that are spaced from one another and wherein the first edgeand the second edge both contact the internal surface of the catheterhub in the ready position; a distal end portion of the needle guardbeing biased by a side of the needle into retaining contact with thecatheter hub when the needle is in the ready position, said distal endportion of the needle guard being movable within the interior cavity ofthe catheter hub to a position blocking said needle tip when said needleis in the retracted position and the needle shaft no longer exerts aforce on the distal end portion of the needle guard.
 2. The catheterassembly of claim 1, wherein the interior cavity of the catheter hubcomprises a larger inside cross-sectional dimension section distal of asmaller proximal inside cross-sectional dimension section.
 3. Thecatheter assembly of claim 2, wherein the larger inside cross-sectionaldimension section is a groove.
 4. The catheter assembly of claim 1,wherein the reduced diameter shaft section is a circular groove, whichis recessed from the nominal diameter of the needle shaft.
 5. Thecatheter assembly of claim 1, wherein the needle guard further comprisesan arm extending distally from the proximal end and crosses the needleshaft in the ready position, when viewed from a side of the needleshaft.
 6. The catheter assembly of claim 1, wherein the needle guardcomprises an upward sloping arm comprising an edge.
 7. The catheterassembly of claim 1, wherein the reduced diameter shaft section islocated adjacent a relatively larger diameter shaft section.
 8. Anintravenous catheter assembly comprising: a catheter hub comprising aproximal end, a distal end, and an interior cavity having an internalsurface; a catheter tube comprising a lumen attached to the distal endof the catheter hub; a needle hub comprising a needle disposed withinthe lumen of the catheter tube when in a ready position; said needlehaving a proximal end, a needle tip, and a needle surface defining aneedle shaft having a circular groove near the needle tip, said needlebeing movable between said ready position in which the needle extendsinto said catheter tube and a retracted position in which the needle isdisplaced from the catheter tube; a needle guard for shielding theneedle tip slidably mounted on said needle and positioned in theinterior cavity of the catheter hub when in the ready position, saidneedle guard comprising a proximal wall comprising a perimeter definingan opening having the needle passing therethrough, a first arm extendingdistally of the proximal wall, and second arm, which is longer than thefirst arm, extending distally of the proximal wall having a distal endportion biased by the needle into contact with the internal surface ofthe catheter hub; wherein the circular groove is configured to abut thefirst arm to limit distal advancement of the needle guard off of theneedle.
 9. The catheter assembly of claim 8, further comprising a grooveformed on the internal surface of the catheter hub.
 10. The catheterassembly of claim 9, wherein at least a section of the distal endportion on the second arm engages the groove.
 11. The catheter assemblyof claim 8, wherein the proximal wall comprises a first edge and asecond edge that are spaced from one another and wherein both the firstedge and the second edge contact the internal surface of the catheterhub in the ready position.
 12. The catheter assembly of claim 8, whereinthe catheter hub comprises a luer fitting on its proximal end.
 13. Thecatheter assembly of claim 8, wherein the distal end portion comprises adistal wall having a curved end.
 14. The catheter assembly of claim 8,wherein second arm comprises an opening having the needle passingtherethrough.
 15. The catheter assembly of claim 8, wherein the secondarm of the needle guard crosses the needle shaft in the ready positionand when viewed from a side of the needle.
 16. An intravenous catheterassembly comprising: a catheter hub comprising a proximal end comprisinga female luer fitting, a distal end comprising a tapered cone section,and an interior cavity comprising an interior surface; a catheter tubecomprising a lumen attached to the distal end of the catheter hub; aneedle hub comprising a needle having a needle tip and a needle shaftdisposed within the lumen of the catheter tube when in a ready position;said needle further comprising reduced diameter shaft section proximalof the needle tip; a needle guard for shielding the needle tip slidablymounted on said needle and positioned in the interior cavity of thecatheter hub when in the ready position, said needle guard comprising aproximal wall comprising a fixed perimeter defining an opening havingthe needle passing therethrough, an arm comprising an opening having theneedle passing therethrough, and a distal end portion of the arm biasedby a side of the needle shaft into contact with the interior surface ofthe catheter hub; wherein said opening on said proximal wall, saidopening on said arm, and said distal end portion of the needle guardsimultaneously contact the needle during distal movement of the needleguard along the needle.
 17. The catheter assembly of claim 16, whereinthe reduced diameter shaft section is a circular groove.
 18. Thecatheter assembly of claim 16, wherein the opening on the resilient armcomprises a flap and wherein the flap contacts the needle during distalmovement of the needle guard.
 19. The catheter assembly of claim 16,wherein the arm crosses the needle shaft in the ready position.
 20. Thecatheter assembly of claim 16, wherein the proximal wall comprises afirst edge and a second edge that are spaced apart from one another andwherein both the first edge and the second edge contact the interiorsurface of the catheter hub in the ready position.
 21. The catheterassembly of claim 16, wherein the proximal wall comprises a proximallyfacing wall surface and a distally facing wall surface.